On 3/16/21 3:04 AM, Colin King wrote:
From: Colin Ian King <colin.k...@canonical.com>
At the start of the function there is a null pointer check on cma
and then branch to error handling label 'out'. The subsequent call
to cma_sysfs_fail_pages_count dereferences cma, hence there is a
potential null pointer deference issue. Fix this by only calling
As far as I can tell, it's not possible to actually cause that null
failure with the existing kernel code paths. *Might* be worth mentioning
that here (unless I'm wrong), but either way, looks good, so:
Reviewed-by: John Hubbard <jhubb...@nvidia.com>
thanks,
--
John Hubbard
NVIDIA
cma_sysfs_fail_pages_count if cma is not null.
Addresses-Coverity: ("Dereference after null check")
Fixes: dc4764f7e9ac ("mm: cma: support sysfs")
Signed-off-by: Colin Ian King <colin.k...@canonical.com>
---
mm/cma.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/mm/cma.c b/mm/cma.c
index 6d4dbafdb318..90e27458ddb7 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -512,7 +512,8 @@ struct page *cma_alloc(struct cma *cma, size_t count,
unsigned int align,
cma_sysfs_alloc_pages_count(cma, count);
} else {
count_vm_event(CMA_ALLOC_FAIL);
- cma_sysfs_fail_pages_count(cma, count);
+ if (cma)
+ cma_sysfs_fail_pages_count(cma, count);
}
return page;
